Highly-efficient conversion of glycerol to solketal over heterogeneous Lewis acid catalysts

Abstract

The acetalization of acetone with glycerol to yield 2,2-dimethyl-1,3-dioxolane-4-methanol (solketal) was successfully catalyzed by mesoporous substituted silicates including the novel Hf-TUD-1 material. This reaction offers an attractive path for the conversion of glycerol, which is the main side-product in the synthesis of biodiesel, to a valuable compound with potential for industrial applications. The most promising among the heterogeneous catalysts employed in this work, Zr-and Hf-TUD-1 and Sn-MCM-41, display mainly Lewis acid properties as demonstrated by characterization with FT-IR analysis of pyridine adsorption, and achieve superior results compared to a reference solid acid catalyst such as Ultrastable zeolite Y. Especially the newly synthesized Hf-TUD-1, showing the highest conversion and turnover among the screened materials, is a promising catalyst for the acetalization of acetone with glycerol in a sustainable process. The excellent performance of these mesoporous catalysts is ascribed to their combination of acidity, wide pores, large specific surface area and relatively hydrophobic surface.Scheme 1 Solketal prepared from the acetalization of acetone with glycerol. † Electronic supplementary information (ESI) available: Comparison between heterogeneous catalysts for the conversion of glycerol to solketal. See

Integrated reduction and acid-catalysed conversion of furfural in alcohol medium using Zr,Al-containing ordered micro/mesoporous silicates

“…These features are consistent with the materials possessing mesoporosity and an interconnected pore network, where condensation and evaporation may occur via different mechanisms [123][124][125]. The N 2 uptake reached a plateau at high p/p 0 , indicating negligible secondary mesopores or macropores, which is in agreement with the literature for purely siliceous, as well as Al and/or Zrcontaining TUD-1 type materials [75,82,118,[126][127][128][129]. Based on the mesopore size distribution curves (Figure 3b- nm for Zr-TUD-1 and Al-TUD-1, respectively.…”

“…Based on the mesopore size distribution curves (Figure 3b- nm for Zr-TUD-1 and Al-TUD-1, respectively. These results may be partly due to the introduction of relatively bulky zirconium atoms into the framework [118], and/or to differences in rates of hydrolysis and condensation reactions of the metal precursors during sol-gel synthesis [128].…”

Conversion of biomass platform molecules into fuel additives and liquid hydrocarbon fuels

“…Mesoporous silicates bearing Lewis acid sites such as Zr-TDU, Hf-TDU, and Sn-MCM-41 also showed excellent activity for performing the acetalization of acetone with glycerol. 186 The 130 and zirconia and promoted zirconia 188 resulted excellent catalysts able to achieve high selectivity to solketal (80-97%) at near complete glycerol conversion.…”

Pure and Alloyed Copper‐Based Nanoparticles Supported on Activated Carbon: Synthesis and Electrocatalytic Application in the Reduction of Nitrobenzene

“…[39] The hydrophilicity of the materials was estimated from the number of water molecules adsorbed per nm 2 of catalyst surface of carbon material. [40] This number was obtained from the water loss at 25-200 8C, as measured by thermal gravimetric analysis (TGA) in O 2 at a heating rate of 10 8C min…”